Aetna CEO: Obamacare In A 'Death Spiral' Heading Into 2018. Aetna and Humana have called off their deal amid government concerns over competition. Here's a look back at six pivotal moments that led to this. Aetna and Humana have called off their deal amid government concerns over competition.
For the plant genus, see Synapsis (plant). Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.
The particular synapse made between a spinal motor neuron and skeletal muscle cell is called the motor endplate because of its specific structure. The synapse at the neuromuscular junction has three characteristic features of chemical synapses in the nervous system. First, there is a distinct separation between the presynaptic and the postsynaptic membrane. The space between the two is known as the synaptic cleft.